This application claims the benefit of German Patent Application No. 101 36 681.7 filed Jul. 27, 2001.
This invention relates generally to frame structures, and, more particularly, to frame structures for switch cabinets.
A corresponding frame structure is known from DE 198 53 611. The frame structure consists of a plurality of interconnected frame profiles, each frame profile being designed as a hollow profile and subdivided into a first side surface area assigned to the interior of the switch cabinet and into a second side surface area oriented away from the interior of the switch cabinet. The second side surface area is completely closed towards the interior of the switch cabinet, and cover elements can be mounted on laterally projecting fastening webs which are equipped with rows of holes and provided on the second side surface area. A fixation is thereby possible without the creation of a passage to the interior of the switch cabinet, so that sealing is simplified.
Furthermore, a similar frame structure consisting of individual rail profiles or frame profiles, respectively, is described in DE 33 44 598. The frame structure known therefrom for a switch cabinet consists of at least twelve interconnected frame structure legs of the same hollow profile. The hollow profile is here provided with rows of holes and has a substantially square cross-section. In an extension of the associated square hollow profile sides, there are formed profile legs which on the outsides form outwardly projecting frame-like sealing or abutment webs. The various elements arranged on the outside are mounted on the hollow profile by means of screws which are slid through openings on the inside of the hollow profile and arranged with their heads in the interior of the profile. To this end, the profile leg comprises recesses at specific places for positioning connection sleeves of the cover elements. The openings for passing the screws therethrough are, however, fixedly predetermined at specific places only because a sealing is required at each of said places.
Another frame structure consisting of profile bars is described in DE 40 36 664. The tubularly closed hollow profiles are here equipped with an L-shaped wall section directed towards the interior of the switch cabinet and with a wall section which is directed to the outside and stepped in W-shaped configuration. Flanges are provided at the points of intersection of the two wall sections, one of the flanges being supplemented by a double-laid web. Both in its inner wall area and in its outer wall area, the hollow profile is provided with penetrations or holes with which different elements can be fastened.
All of the known profile bars have in common that these are hollow profiles. The hollow profile is needed to give the assembled frame structure the necessary dimensional stability. This is particularly necessary for building up a cabinet, in particular a switch cabinet, because walls, ceilings, floors and doors or flaps can be anchored in a reliable and stable manner to the hollow profiles. However, it has turned out to be a disadvantage that it is not easily possible to fix more than two rod-like carrier elements to each of the profile bars within the frame structure in one and the same installation plane. Furthermore, the individual profile bars are very heavy, thereby contributing considerably to the overall weight of the switch cabinet.
In this respect profile bars that are configured to be open in cross section would be usable in a much more flexible way because these offer more possibilities of accommodating something. One shortcoming of such open profile sections is however that they have a relatively small dimensional stability due to their half-open cross-sectional configuration over their entire length. This is in particular disadvantageous when the frame structures are to be built into cabinets by mounting additional walls, ceilings, floors, doors or flaps because the stability of the profile bars is not sufficient.
In one aspect, a frame structure for a switch cabinet is provided. The frame structure comprises at least four vertically extending rail profiles arranged in edges. At least one of said vertical rail profiles comprises a cross section formed by a plurality of bent profile webs, and the cross section of an envelope of the at least one rail profile is configured to be rectangular. The at least one vertical rail profile is configured to be open, and at least one profile web extends longer than an edge length of the rectangle formed by said envelope and is double-walled.
The frame structure provides for an open profile of an adequate stiffness comparable to the stability of closed profiles. Adequate stiffness is ensured by the double-walled profile web which is arranged in the interior of the rail profile and which in comparison with the other existing profile rods is configured to be particularly long and stable. A flexible installation of the most different assembly elements in the interior of the switch cabinet is thereby ensured together with a high dimensional stability of the open rail profiles. The frame structure may be inexpensively manufactured and assembly is simplified.